Auchenlaich is the longest megalithic burial cairn in Britain. Auchenlaich Cairn consists of a ridge of grassed over stones which stretches for over 350 metres in a perfectly straight line, from a field behind Auchenlaich farm and well into another field to the north. The farm track cuts right across the middle of the cairn. Auchenlaich long barrow runs in a NNW to SSE direction.
There is one burial chamber opened in the south section of the monument and there are also small piles of what looks like recently excavated stones along the south section.